17-4 Stainless Steel Sheet/Plate , also known as 17-4PH Precision Hardening is normally used in natural gas/petroleum/oil, aerospace, thermal, and chemical applications. 17-4 stainless has high tensile strength and hardness and excellent corrosion resistance up to high temperatures. 17-4 sheet/plate stock is available in full size and custom cut lengths. This material meets the following specifications: AMS 5604, ASTM A693, and ASTM F899 (chemistry only for thicknesses up to 1/4").